Avaliação de metais pesados no camarão da Amazônia Macrobrachium amazonicum em diferentes pontos da foz do rio Amazonas

Abstract

The Amazon Shrimp, Macrobrachium amazonicum, is a species of shrimp widely collected and consumed by the riverside population of the Amazon River basin, having a great local economic importance. Thus, in view of the degradation of natural environments by anthropic action, studies on the concentration of heavy metals in this species are important to obtain results on bioaccumulation, physiological damage to animals, and food security for the population. Thus, the aim of this study was to evaluate the concentration of metals copper (Cu), manganese (Mn), lead (Pb), and chromium (Cr) in muscle tissue, organs (heart, gonads, and hepatopancreas), and exoskeleton (residue) of male and female shrimp M. amazonicum from Amazon River. Ninety shrimp were collected in three regions of Amapá (mouth of the Mazagão Velho River in Mazagão, Santana Island in the Municipality of Santana, and the Bailique River Archipelago), with the aid of a trap, they were stored, transferred to the laboratory, weighed and measured. The muscle, organs, and exoskeleton were individually weighed, lyophilized and crushed. Heavy metals Cu, Mn, Pb and Cr were determined in triplicate. The experiment was designed in a 2 x 3 factorial scheme (sex and location). The normality test applied was the Shapiro-Wilk. For normal variables, the ANOVA test was applied, followed by Duncan's test, and for non-normal variables, Kruskal-Wallis test was applied (5% significance). Males were larger than females (p <0.05). Mazagão specimens showed greater length and total weight (p <0.05). There was a higher concentration of Mn and Pb in males when compared to females (p <0.05). Bailique specimens had a lower concentration of Cu and Mn (p < 0.05). Mazagão specimens had lower Pb concentrations and males collected on Santana Island and Bailique had higher Pb concentrations (p <0.05). The specimens collected in Ilha de Santana had lower Cu contraction, however, the females collected in Mazagão had a higher concentration of Cu. There was a higher concentration of Cu in the organs; a higher concentration of Mn in male residues and; a higher concentration of Cr in the organs, not differing between males and females (p >0.05). A lower concentration of Cu was observed in the organs in Bailique and males accumulated a greater amount of Mn. In Bailique and Ilha de Santana, there were higher concentrations of Pb in the muscle and in the residue of males when compared to females. Higher concentration of Pb in the tissues of females in most places and tissues studied. In view of the high levels of metals observed in the animals collected at the three study points compared to the maximum levels recommended by environmental agencies, further studies are advised regarding the areas where animals are captured for their consumption and cultivation. Keywords: Amazon, aquaculture, bioaccumulation, shrimp farming.